13. What words of reproof does Jesus next give the Christians in Pergamum, and why did the congregation need them?

¹³ Jesus further reproves the Christians in Pergamum, saying: “So you, also, have those holding fast the teaching of the sect of Nicolaus likewise.” (Revelation 2:15) Previously, Jesus has commended the Ephesians for their hatred of the deeds of this sect. But the Christians in Pergamum need counsel on keeping the congregation free from sectarianism. More firmness is needed in upholding Christian standards so that the unity for which Jesus prayed at John 17:20-23 may be preserved. It is necessary “both to exhort by the teaching that is healthful and to reprove those who contradict.”​—Titus 1:9.

14. (a) From early days, with whom has the Christian congregation had to contend, and how did the apostle Paul describe them? (b) What words of Jesus should be heeded by any who may have become inclined to follow a breakaway group?

¹⁴ From early days, the Christian congregation has had to contend with proud apostates, who by smooth, deceptive speech “cause divisions and occasions for stumbling contrary to the teaching” provided through Jehovah’s channel. (Romans 16:17, 18) The apostle Paul warned of this threat in almost all his letters.a In modern times, when Jesus has restored the true congregation to its Christian purity and unity, the danger of sectarianism remains.

15. How does sectarianism get started?

¹⁵ How does sectarianism get started? Perhaps a self-styled teacher sows doubts, disputing some Bible truth (such as our being in the last days), and so a splinter group breaks off and follows him. (2 Timothy 3:1; 2 Peter 3:3, 4) Or someone criticizes the way Jehovah is having his work done and appeals to a self-sparing spirit by claiming that it is neither Scriptural nor necessary to go from house to house with the Kingdom message. Sharing in such service after the example of Jesus and his apostles would keep these ones humble; yet, they prefer to split off and take it easy, perhaps only reading the Bible occasionally as a private group. (Matthew 10:7, 11-13; Acts 5:42; 20:20, 21) Such ones concoct their own ideas about the Memorial of Jesus’ death, the Scriptural command to abstain from blood, celebration of holidays, and the use of tobacco. Moreover, they downgrade Jehovah’s name; very soon they fall right back into the permissive ways of Babylon the Great. Even worse, some are moved by Satan to turn upon and ‘beat their fellow slaves,’ their onetime brothers.​—Matthew 24:49; Acts 15:29; Revelation 17:5.